Buck,
Thanks so much. I've been wanting your input on this, but hadn't gotten around to a private message. The "complete" markings are:
Lower tong, right side: "45--75 / PAT. SEPT 14, 1880" (two lines)
Lower tong, left side: "MANUFACTURED BY THE / WINCHESTER REP. ARMS CO. / NEW HAVEN, CONN. U.S.A" (three lines)
So, I'm not sure if "ONLY" is the correct word.
Hugh